Oil Dipstick plug?

If it is a front drain plug:
That front plug holds about 3/4 of a quart of oil (oil that isnt drained if the plug isnt removed).

I'd do as Anthony mentioned, but try to find magnetic plugs. A lot of the crap at parts stores is not magnetic. LRS wants a pretty penny for magnetic plugs though.

You might be able to replace the washer instead (I need to do this myself - my plastic washers have seen better decades).

Good luck.

If it is the dipstick plug try Clevite P/N 219-2185 which is a steel expansion cup plug for the dipstick hole. You can get it at NAPA.

If you are talking about the dipstick hole in the timing cover on the passenger side, where the dipstick used to be in 289 days, my guess is 1/4 in. There are numerous size cup plugs that should fit. Or just thread a bolt into it. The country boy would silicone or JB weld it.....